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(No Model.)

I. M. POLLARD. Process of, and Apparatus for, Extinguishingf'ires.

No. 237,899. Patented Feb. 15,1881.

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' UNITED STATES PATENT EFICE.

JAMES M. POLLARD, OF NEW ORLEANS, LOUISIANA, ASSIGNOR TO'GEORGE H.ROBINSON, IN TRUST FOR THE FIRE EXTINGUISHER MANUFACTUR- ING COMPANY, OFNEW YORK, N. Y.

PROCESS OF AND APPARATUS FOR EXTINGUISHING FIRES.

SPECIFICATION forming part of Letters Patent No. 237,899, dated February15, 1881.

Application filed March 31, [880. (No model.)

To all whom it may concern Be it known that I, JAMES MADISON POL- LARD,a citizen of the United States, residing at New Orleans, in the parishof Orleans and State of Louisiana, have invented new and usefulImprovements in Process of and Apparatus for Extinguishing Fires, ofwhich the following is a specification.

My invcntionrelates to that class of processcs and apparatus in whichcarbonic-acid gas in large volume is evolved and employed to extinguishfires by its direct application thereto; and it is especially designedand intended for use on shipboard and in places where it'can bepractically confined, such as in mines, tunnels, and tightly closedwarehouses or buildings.

Owing to the very large quantity of chemicals which are necessarilyemployed to sup 2'0 ply the required volume of carbonic-acid gas, it hasbeen long desirable to dispense with the use of free sulphuric acid inextinguishers of this class. It is troublesome to handle or transportthe free acid in large quantities,and

2 5 the constant pressure of several hundred gallons on a vessel wouldprove almost as great an element of danger as the contingency of fire onshipboard. It'also ultimately corrodes and destroys the apparatus inwhich it is used,

0 so that its use under the requisite pressure is unsafe.

Of the plans or devices designed to obviate the above-mentioneddifficulties and objections, that set forth in Patent No. 196,562,granted to 5 J. H. Connolly, October 30, 1877, is by far the mostpracticable and meritorious. It consists in the employment of thesulphuric acid in chemical combination with a base for which it has lessaffinity than for sodium,and in which 4.0 condition, being perfectlyinert and neutral, it

is harmless and non-corrosive. 111 this condition, also,it possessestheveryimportant advantage that, while the reaction is in every way ascomplete and perfect ,as though free sulphuric acid were used, it is notso energetic and violently sudden in liberating carbonic acid aswhen'free sulphuric acid in largevolume is used on equivalent quantitiesof carbonates.

In carrying out my'inven tion I employ the sulphuric acid,'incombination with a base, as above, preferably the salt known as sulphateof alumina, deprived of mostof its water. In this form it is a whiteporous powder, extremeily soluble, requiring but its own volume, by

measure, of cold water and less than half its 5 5 weight of hot water toform a perfect solution.

The object of my invention is to provide an apparatus in which thecarbonate of soda and sulphate of alumina, or equivalent salts, may

be kept indefinitely without being in contact with each other, andmingled at pleasure in such quantities and with such rapidity as may bedesired, the pressure, however, always antomatically stopping theprocess whenever it reaches a fixed limit-say the safe workingpressureof the apparatus.

I am aware that it is not new to carry these or similar chemical agentsinclosed separately in a fire-extingisher with devices for mingling themand generating the gas, when required, the distinction between myinvention and machines of this class beingin the quantities of materialthat may be used.

All machines in which a liquid compound of the chemicals used is forcedby the pressure generated by their reaction upon the tire are designedto use only sufficient chemicals to produce the pressure found mostdesirable and effective, and to this end all the chemicals are mixed atonce and agitated together. This plan is inadmissible in a dry-gasmachine, in which it is necessary, owing to the largevolumeofcarbonic-acid gas compared with its containing-vessel, that thechemicals should be gradually min glcd and the pressure kept with- 8 5in certain limits; hence I dispense entirely with all plans in which thechemicals are mingled by the action of gravity, such as where 'onereagent is elevated above the other and dropped into the latter, orwhere an elevated 0 acid-receptacle is used and supplied to thegenerating-vessel by means of a conducting-pipe and a suitableequalizing-pipe, as in either case the pressure can go on increasing toa dangerous or destructive degree.

My invention consists in a process of mingling the chemicals employed inthe production of carbonic acid by blowing or forcing, by

steam or other aeriform fluid, one of the materials employed intocontact or admixture with the other in confinement, the dilference inpressure between the gas and the power employed causing the chemicals tomingle gradually, equalization of pressure automatically stopping thefurther mingling of the chemicals until, by using or otherwise disposingof the generated carbonic acid, the equilibrium is disturbed andmingling resumed.

My invention further consists in certain improvements in apparatus bywhich the process is carried into effect, as more fully hereinafterspecified.

Referring to the drawings, Figure 1 shows a side elevation of one of thecylinders or generators of myimproved fire-extinguisher; and Fig. 2, atransverse vertical section of two generators, with side elevation ofthe connecting drum or receptacle above them. Fig. 3 represents a topview of the man-hole or hand-hole, showing the method of inserting thecover through the same. Fig. 4: represents a top view of the man-holewith the cover secured against its seat; and Fig. 5, a view, partly insection and partly in elevation, of the manhole and cover.

In practice two generators are generally employed, connected together bya dome; but it is not, however, essential that the generators should bein pairs, as such arrangement is simply for convenience in maintaining aconstant supply of gas by recharging one generator while the otherisused. As the generators are identical, a description of one will sufficefor both.

The letter A indicates the generator, consisting of a strong vessel ofsteel, boiler-plate, or other suitable material, and is generally ninefeet in length by three feet in diameter, or thereabout. It is dividedinto two compartments, B O, of unequal size, by means of the partitionD, (indicated by the dotted line, Fig. 1.) Each compartment is providedwith a suitable manhole or hand-hole, as at E, which may be closed by asuitable door, preferably arranged to open inwardly.

The letter B indicates a pipe extending longitudinally along the lowerpart of the generator, provided with a valve, S, and connecting with asteam-boiler, preferably the main boiler of the engine, or the boilerot' the donkey-engine of a ship, or in some instances with both.

The letter T indicates a pipe connecting with the steam-dome of theboiler or boilers, and with the chambers B U of the generator by meansof branch pipes U V, which are provided with valves V Z.

The pipes It and T are connected by means of a pipe, A, provided with avalve, B, by means of which communication can be estabtablished betweenthe two or cut off from the same.

The letter C indicates a valve located in the pipe R between the branchpipes l) and F, which lead from pipe R to the respective compartments Band O. The branch pipes D and F, respectively, are provided with valvesG and I, by which communication with the pipe R and the respectivecompartments may be cut off or established at will, as more fullyhereinafter explained. The pipe 11 is bent downwardly from the pipe R,and enters the compartment B at the bottom, and is provided with avalve, K. The branch pipes D and F, after euteri n g the respectivecompartments, are bent laterally, as indicated in Fig. 2, for thepurpose to be hereinafter explained.

The letter L indicates a transverse drum extending over the generatorsA, when two of the same are employed, and connected with the same bymeans of the pipes M, (shown in dotted lines, Fig. 1,) the said pipesbeing provided with valves N, by means of which either of saidgenerators may be put into communication with the dome.

0 indicates a vertical receiver connected to the drum, and to atransverse pipe, 1 at its lower end, the said pipe being connected tothe compartments B and G at their bottoms by means of branch pipes It,as shown. The reservoir and branch pipes are provided with valves M, bymeans of which communication with either of the compartments 0 or thereceiver 0 may be established to draw oft the contents of the same, asmore fully hereinafter specified. The lower end of the reservoir 0 isprovided with a valve, T, by which its contents may be discharged, andthe drum L with an escape-pipe, 1

The letter U indicates two pressure-gages, one applied to eachcompartment 0 and B. The letter a indicates a series of pet-cocksextending from the chamber B, through which the air may be expelled fromthe same, as more fully hereinafter explained.

The'operation of my invention is as follows: Into the smallercompartment of the generator the sulphate of alumina is introduced so asto completely fill the same-say one thousand pounds of the same, orthereabout. Into the larger eompartmentan equivalentofsodiumbicarbonate,-say seven kegs, or seven hundred and eighty-fourpoundsisplaced. The man or hand holes, which have been previously opened for theintroduction of the chemicals, are now closed and the machine is readyfor use, with the chemicals separate from each other and hermeticallysealed from contact with the atmosphere. The valve 0 being closed,valves G and S are opened, permitting hot water from the boiler to flowthrough pipe B and branches D to chamber B, the confined air beingpermitted to escape through the open pet-cocks successively, which areclosed one after the other as the water reaches their respective levels.When the said chamber B is completely filled the valve S is closed andthe valve W opened, permitting steam from the boiler to exert itspressure directly upon the solution in chamber B. The valves G are thenclosed and the valves 0, K, and I opened, the steampressure in thechamber B rapidly forcing the chemical solution from said chamberthrough pipes H R and branches F to chamber and into intimate contactwith the sodium bicarbonate therein. The gas liberated by the reactionof the two reagents creates a pressure in the chamber 0 and connections,which continually approximates to the steam-pressure in the chamber B,thus diminishing the force of the flow of the alumina solution until anequilibrium is established between the two chambers, when no morealumina solution will be forced into chamber G, except when required orcaused to do so by using a portion of the gas contained in O, and thusdestroying the equilibrium. The evolution of gas is thus automaticallyregulated by the rapidity with which it is used. When the aluminasolution is all forced into the chamber 0 the steam will follow from thechamber B and thoroughly agitate and mingle the chemicals in saidchamber C. This will be indicated by the sound of the steam in passingthrough valve K, which valve should be then closed and the valve Sopened, allowing an additional volume of Water to flow into chamber 0,which should be filled up to the pet-cock s, when the valve S is to beclosed and the valve B opened. This permits steam to flowthrough pipes AR and branches F to chamber 0 and thoroughly agitate the chemicalstherein. This agitation should continue for a few moments, during'whichtime the valves 1 should be alternatel y closed and opened, so that thesteam will enter chamber 0, first at one end and then at the other, thusthoroughly moving and mingling the chemicals, after which the valve 0should be closed.

7 It will be borne in mind that the valves G, K, and I do not interruptthe passage-way through pipe R, but simply close and open the branchesD, H, and F at theirjunctions with said pipe.

When the gas in O is all evolved,which will be indicated by thepressure-gage, the valve Z is opened and steam admitted, which willserve the double purpose of driving the gas from thechamber G and drum Lout of the apparatus, and by opening the valve S will expel the residuumor sulphate of soda and hydrate of alumina remaining in the vessel. Whenthe residuum is entirely expelled the valves W and Z are closed, whenthe remaining steam in the vessel will pass off through S, leaving thevessel empty and in condition to be recharged.

The pipes I), which enter the chambers some distance from their centralportions, being bent at sharp or right angles to the bottom, prevent thechemicals from entering said pipes when the apparatus is not in use,and,

"blowing or forcing, by steam or other aeriform fluid, one of thematerials employed into contact or admixture with the other inconfinement, the difference in pressure between the gas and the poweremployed causing thechemicals to mingle gradually, and equalization ofpressure automatically stopping the further mingling of the chemicalsuntil,by using or otherwise disposing of the generated carbonic acid,the equilibrium is destroyed and the mingling resumed, essentially asset forth.

2. In a chemical fire-extinguisher, the combination of the twocompartments for containing the reagents, and a pipe connecting the samewith the lower part of the steam-boiler, and the connecting-pipesleading to the respective compartments, the said pipes being providedwith suitable valves, whereby hot water may be admitted to onecompartment and the contents, when dissolved, transferred to the secondcompartment, substantially as specified.

3. In combination with the compartments for containing the reagents, thehot-water pipes and steam-pipes proceeding from the steam and waterportions of the boiler to the upper and lower parts of the respectivecompartments, and provided with suitable valves, whereby either hotwater or steam may be ad'- mitted to either of the compartments,substantially as and for the purposes specified.

4. The combination, in a fire-extinguisher, of the two vesselsconstructed with separate compartments for the reagents, and providedwith suitable connections extending from a steam-boiler, and suitablevalves for supplying the compartments with water and steam, theconnecting-pipes leading to the exits of the gas and waste solutions,and the controlling-valves, whereby the vessels may be alternately usedand recharged, substantially as specified.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

J. M. POLLARD.

Witnesses:

JAMES L. NORRIS, JAMES A. RUTHERFORD.

